DETROIT, MI - JULY 1: Center fielder Bradley Zimmer #4 of the Cleveland Indians lays out to catch a fly ball hit by Mikie Mahtook of the Detroit Tigers in the first game of a doubleheader during the second inning at Comerica Park on July 1, 2017 in Detroit, Michigan. (Photo by Duane Burleson/Getty Images) less

DETROIT, MI - JULY 1: Center fielder Bradley Zimmer #4 of the Cleveland Indians lays out to catch a fly ball hit by Mikie Mahtook of the Detroit Tigers in the first game of a doubleheader during the second ... more

Photo: Duane Burleson, Getty Images

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Bradley Zimmer takes a hit away from Detroit’s Mikie Mahtook with a diving catch in center July 1. For an encore, Zimmer robbed Mahtook of another hit in the second game that day.

Bradley Zimmer takes a hit away from Detroit’s Mikie Mahtook with a diving catch in center July 1. For an encore, Zimmer robbed Mahtook of another hit in the second game that day.

Photo: Duane Burleson, Getty Images

Image 3 of 7

Cleveland center fielder Bradley Zimmer was hitting .274 with five homers after his first 52 games in the major leagues.

Cleveland center fielder Bradley Zimmer was hitting .274 with five homers after his first 52 games in the major leagues.

Center fielder Bradley Zimmer watches the game next to head coach Nino Giarratano, left, during a game against UC Santa Barbara at Dante Benedetti Diamond at Max Ulrich Field May 16, 2014 in San Francisco, Calif. less

Center fielder Bradley Zimmer watches the game next to head coach Nino Giarratano, left, during a game against UC Santa Barbara at Dante Benedetti Diamond at Max Ulrich Field May 16, 2014 in San Francisco, ... more

Zimmer is a 6-foot-5, 220-pound outfielder from USF who hits left-handed and throws right-handed. He’s batting .265 with five homers in 162 at-bats. He has stolen 10 bases in 11 attempts.

The Indians’ 2014 first-round pick received “who you are is plenty good enough” advice during his freshman season with the Dons from head coach Nino Giarratano.

“I heard him say a bunch of times, ‘Just be Bradley Zimmer.’ I think I put a little bit of pressure on myself my first year, trying to do a little too much,” Zimmer said.

After hitting .242 with no homers as a freshman, Zimmer improved to .320 with seven home runs as a sophomore and .368 and another seven long balls as a junior.

The Indians got swept in a three-game series in Oakland over the weekend and opened this week with three games at AT&T Park. The extended Bay Area stay has enabled Zimmer to see some of his friends and former teammates from the Hilltop.

One man who won’t connect with Zimmer in this stretch: Giarratano. He’s watching his son Nico play for the Giants’ Arizona League team. San Francisco selected Nico, an infielder, in the 24th round of last month’s draft.

During a phone interview, Nino Giarratano recalled he could envision Zimmer becoming a big-leaguer “probably from the very first day that I saw him. He was just big and strong, and he just looked so much different than everybody else.

“The tool set really just kind of jumped out at you: He could throw it. He could run. He could hit for power. He just needed to put it all together, and then once it all came together, it was magical.”

Giarratano referred to two moments that encapsulate Zimmer’s career at USF, each of which came at old Benedetti Diamond: a back-to-the-plate, leaping catch on which he crashed into the base of the center-field fence and a 280-foot line drive to left that Zimmer turned into a triple.

“When he rounded second base and was heading to third,” Giarratano said, “your jaw just dropped and you’re like, ‘Nobody hits a triple at 280 feet,’ but Bradley could do that.”

Zimmer put himself on the major-league highlight reels July 1 in a doubleheader at Detroit. In the opener, he raced into right-center to make a diving grab of a Mikie Mahtook liner. In the second game, Zimmer robbed Mahtook again, this time with a full-extension, backhanded catch in deep left-center.

“He’s been a real bright spot for us,” Cleveland manager Terry Francona said. “He’s played a terrific center field. His tools really stand out; you can see the speed and everything.”

Francona tried to walk that fine line of extolling Zimmer’s potential without adding undue expectations.

Said Francona: “What’s he going to grow into: Is he going to be a (hit-for-average) guy? Is he going to be a power guy? Is he going to be both? How many stolen bases?

“There’s a lot to like, but ... the game is hard enough at this level. We just want to let him play.”

Zimmer played one season at USF with his brother Kyle, a pitcher whom the Royals selected in the first round in 2012. Injuries have sidetracked Kyle’s pro career — he has a 7.52 ERA in 11 outings with Triple-A Omaha this season — but he remains one of his younger brother’s biggest backers.

Bradley said that Kyle has been “awesome. He’s extremely happy for me.”

The three games in Oakland certainly didn’t make Bradley happy. Not only did Cleveland get swept, but also he went 0-for-6 with four strikeouts (and two walks). He was 0-for-5 with a run scored Monday.

Chalk up this stretch to Bradley Zimmer’s continuing education at the big-league level.

“The game’s a little quicker and there are a lot more people here,” he said. “Control your breath and have fun. It’s the same game.”